428
FXUS62 KFFC 171858
AFDFFC

Area Forecast Discussion
National Weather Service Peachtree City GA
258 PM EDT Fri May 17 2024



...Afternoon Area Forecast Discussion...

.SHORT TERM...
(This afternoon through Saturday)
Issued at 255 PM EDT Fri May 17 2024

So far today, dense cloud cover and the stabilizing effect of
showers have precluded deep convection across the majority of the
CWA. The exception has been the southwest portion of the CWA,
where a west-to-east oriented line of convection has shifted
eastward out of south-central AL. WPC has introduced a Moderate
Risk for excessive rainfall and flash flooding across our far
southwestern counties, where moderate to heavy rainfall and
elevated/embedded thunderstorms have been occurring since mid-
morning. While instability is not particularly exceptional, PWAT
has surged to 1.7+ inches and 925-850 mb frontal convergence is
strong, so the expectation is that this messy area of convection
will persist into the evening, and possibly become better
organized. Thinking that the potential for severe storms is
marginal at best across our southern couple rows of counties, as
instability has not been able to nose northward from the Gulf
Coast much due to the cold pool produced by the area of
convection. In the event of a strong or marginally severe storm
across our southern tier this afternoon or evening, damaging wind
gusts would be the primary threat. Will likely have scattered
showers and possibly isolated thunderstorms persist overnight as
the moist, southwesterly flow persists.

On Saturday, a shortwave trough coupled with progged MUCAPE of
1500- 3000 J/kg will be more than enough lift/instability to fire
off scattered to widespread convection across much of the CWA
during the afternoon and evening. SPC has a Slight Risk along and
south of a line generally from Eatonton to Macon to Columbus,
where 0-6 km bulk shear around 40-80 kts coupled with mid-level
lapse rates of 6.5-7.0 deg.C/km support the potential for damaging
wind gusts and hail. A Marginal Risk encompasses much of the
remainder of the CWA as the environment farther north is also
supportive of scattered thunderstorms with some strong convection
likely. A possible caveat to coverage and/or intensity of storms
will be how quickly/how much cloud cover clears out. Another
possible caveat... Some of the CAMs indicate a morning MCS
tracking along the Gulf Coast with showers and embedded storms
across portions of central GA, which could impact airmass recovery
in the afternoon. Given the dynamic, unstable environment,
isolated to scattered showers and storms could persist well after
sunset into the overnight hours.

Martin


&&

.LONG TERM...
(Sunday morning through next Thursday)
Issued at 255 PM EDT Fri May 17 2024

Starting off the forecast period with Sunday morning the
troughing associated with this weekends system will begin to move
eastward into the Atlantic. For Sunday, the vorticity couplet will
still be over eastern Georgia as well as a weak moisture axis
which will result in showers still lingering over eastern GA. With
this last piece of energy in our area, this will give way to just
enough energy to produce the chance for thunderstorms over
eastern Georgia through Sunday night.

After Sunday a long wave ridge sets up over almost the entire
eastern third of the CONUS. This along with the lack of moisture
over the area will lead to a drier time for most of Georgia
beginning Monday and lasting until Wednesday. The unfortunate
piece to this is that temperature will quickly rise with many area
reaching close to 90 which goes in line with the CLimate
Prediction Center`s 6-10 day outlook showing above normal
temperatures.

While this riding is dominating our area, the low pressure system
to the west will track into the Great Lakes region, not
particularly affecting the ridging. This will give way for the
potential for a small burst of vorticity and moisture to move into
Tennessee and northern GA by Thursday which could ultimately
result in some shower activity for northern GA. Should this system
have enough energy it will pave the way for more of a distinctive
troughing feature to move eastward into Georgia and the southeast
to push the riding to the east. Models are remaining split on
whether this will happen or not a week from now, so will see what
the models indicate in subsequent runs. With any showers, the risk
for thunderstorms remains over the area simply due to day time
heating.

Temps will stay in the upper 80s over much of the area unless the
troughing is able to make it down to this area but this actually
is only 4-6 degrees above normal for this time of year. Definitely
trending towards the warmer summer time conditions (bummer for
this cool weather fan).

Hernandez


&&

.AVIATION...
(12Z TAFS)
Issued at 733 AM EDT Fri May 17 2024

Ceilings will lower to MVFR by 15z, in addition to showers
becoming more widespread. Chances for thunderstorms appear to be
greatest this afternoon with forcing from a disturbance aloft
combined with diurnal instability. As such, TEMPOs have been
introduced for TSRA at all sites for either 17z-21z or 18z-22z.
Winds will be E to SE at 4-8 kts. Winds may briefly shift to SW
this afternoon in portions of central Georgia. Ceilings are
forecast to lower to IFR after 00z at the northern TAF sites.

//ATL Confidence...12Z Update...
Medium confidence on progression of ceilings and convection.
High confidence on all other elements.

Martin/King


&&

.PRELIMINARY POINT TEMPS/POPS...
Athens          64  79  62  79 /  80  70  50  50
Atlanta         66  79  64  81 /  70  70  50  40
Blairsville     60  75  59  77 /  80  70  50  60
Cartersville    64  79  61  82 /  70  70  50  40
Columbus        69  80  65  84 /  70  70  40  40
Gainesville     66  78  63  79 /  80  70  50  60
Macon           68  79  65  82 /  70  70  40  50
Rome            65  80  62  83 /  50  70  50  30
Peachtree City  66  79  63  82 /  70  70  40  40
Vidalia         71  84  67  83 /  60  70  50  70

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...Martin
LONG TERM....Hernandez
AVIATION...Martin